Histamine intolerance vs. scombroid fish poisoning
Histamine intolerance
Scombroid fish poisoning
Clinical symptoms due to an imbalance between histamine exposure in foods and the histamine degrading capacity of the patient
Symptoms usually consistent with physiologic effects of histamine and occur minutes-hours after ingestion of foods/beverages containing high levels of histamine
Healthy (non-histamine intolerant) individuals tolerate these same foods without symptoms
Etiology unclear, but a genetic deficiency or drug/alcohol-induced inhibition of histamine degrading enzymes may play a role
Reported to play a role in some adult patients with AD or chronic urticaria (improvement with histamine-free diet)
Symptoms (similar to physiologic effects of histamine) minutes-hours after ingestion of fish containing high levels of "scombrotoxin"
Scombrotoxin - a combination of histamine, other biogenic amines, and potentially other unknown mediators that form as a result of bacterial enzymatic decomposition of fish protein due to inadequate cooling
Affects any person that ingests an adequate amount of the the affected fish (e.g. cafeteria outbreaks)
Fish species often implicated in scombroid fish poisoning:
Scombridae fish family: various types of tuna, wahoo, bonito, mackerel
Other families: Mahi-mahi, anchovies, herring, marlin, salmon, yellow-tail, swordfish
A dose of histamine that would normally be tolerated as orally administered pure histamine may cause symptoms when the equivalent dose is ingested within affected fish, suggesting the importance of mediators other than histamine in scombroid fish poisoning
Anaphylaxis vs. scombroid fish poisoning
Many people dining at the same table can be affected by scombroid (anyone ingesting significant amounts of the fish) vs only the individuals with fish allergy
Cutaneous symptoms of scombroid are usually somewhat different, consisting of a prolonged flush with only modest or no urticaria
In scombroid, plasma and 24-hour urinary histamine metabolite levels will be elevated, but the serum tryptase level remains normal
Note:
Except in the case of scombroid fish poisoning, most individuals tolerate massive amounts of histamine orally (e.g. 500 mg, either in foods or as pure histamine) due to rapid degradation by intestinal diamine oxidase
Histamine not inactivated by cooking or freezing
Ingested histidine may be converted to histamine by human enteric bacteria
If symptoms primarily associated with wine, consider alternative causes of adverse reactions to wine
Consider role of drugs and alcohol that may inhibit DAO activity, resulting in increased histamine blood level after ingestion of histamine-containing foods/beverages:
:
Testing
it may be possible to determine scombroid fish poisoning by testing (fresh prick to prick) with the actual fish meat that caused a reaction
Vitamin B6 and vitamin C - may increase DAO activity
Caution with therapies associated with mast cell degranulation: opiates, contrast media, possibly immunotherapy, etc.
Unknown whether these patients have an increased risk of severe anaphylactic/anaphylactoid reactions, but avoidance or pre-medication with antihistamines may be considered
Table of Contents
Background
Definition
Note:
Histamine Effects
Normal range 0.3-1 ng/mL
Histamine Metabolism
Red box = assay available
Histamine in Foods
Diagnosis
Differential diagnosis
- Consider differential diagnosis for anaphylaxis
- Food allergy
- If symptoms primarily associated with fish, consider
- Food poisoning by natural fish toxins (Ciguatera fish poisoning), bacteria
- IgE-mediated allergy to fish or contaminating shellfish
- Scombroid fish poisoning
- If symptoms primarily associated with wine, consider alternative causes of adverse reactions to wine
- Consider role of drugs and alcohol that may inhibit DAO activity, resulting in increased histamine blood level after ingestion of histamine-containing foods/beverages:
:Testing
Sciotec (Austria) DAO Rea, DAO_HIT
Elimination diet and challenge
Treatment
References